Digital image compression utilizing shrinkage of subband coefficients
US6853318B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 2003 |
| Grant date | Feb 8, 2005 |
| Priority date | — |
| Expiry date | Dec 30, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/13
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In compressions of digital images having a plurality of initial pixels, an image type and a quantization step-size set preassigned to the image type, are associated with a respective coordinate of each of the initial pixels. The digital image is decomposed to produce a plurality of subbands. Coefficients of the subbands define a plurality of resultant pixels, each having a respective one of the coordinates. The subband coefficients also define, for each subband coefficient, a group of resultant pixels to which the subband coefficient contributes. After the decomposition, each of the subband coefficients are shrunk by a respective adjustment that is a function of the respective quantization step-size sets associated with the coordinates of the resultant pixels to which the subband coefficient contributes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.